Substation locking apparatus



Jan. 10, 1950 H. F. OBERGFELL SUBSTATION LOCKING APPARATUS Filed March 4, 1944 INVENTOR. HERBERT F. OBERGFELL, DECEASED AMANDA OBERGFELL, EXECUTRIX 4%,Z

ATTOR NEY Patented Jan. 10, 1950 SUBSTATION LOCKING APPARATUS Herbert F. Obergfell, deceased, late of River Forest, 111., by Amanda Obergfell, executrix, River Forest, 111., assignor to Automatic Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application March 4, 1944, Serial No. 525,019

2 Claims.

This invention relates in general to improvements in substation locking apparatus, but is particularly concerned with an improvement In the switching mechanism in the telephone set.

In telephone sets of the present type it has been the usual practice to operate the switching contacts by lifting the hand set from its rest or holder which would cause an operating plunger or button to move and operate contacts to switch the substation circuits from a signalling to a talking position.

Applicants invention consists in the provision of an arrangement of the switching mechanism, controlled by the hand set, so that it is normally locked against operation and can only be operated after the removal of the hand set from its support, by a manual operation to release the locking device.

The invention is an improvement over the type of switch shown in Obergfell Patent No. 2,133,468, issued October 18, 1938.

The one sheet of drawings comprising Figs. 1-6 inclusive, taken in connection with the following detailed description is believed to be sufficient to make the invention clear.

Fig. 1 is a perspective front view of a wall telephone illustrating my invention and showing a hand set on its support held by spring clips.

Fig. 2 is an enlarged detailed side view of one of the wire spring clips shown in Fig. 1. These clips tend to prevent displacement of the hand set.

Fig. 3 is a front view of the switch mechanism showing the switch mechanism and locking device in normal position, and showing only a partial section of the support on which it is mounted.

Fig. 4 is a bottom view of Fig. 3, also showing the switch mechanism and locking device in normal position also showing only a section of the self support.

ig. 5 is a view taken from the back of Fig. 4 showing the switch mechanism as a, unit separate from its mounting bracket.

Fig. 6 is a view, partly in section, of the looking release button I! of Figs. 1, 2 and 4 showing the details of its mounting.

Referring to the drawings the device will now be described in detail: As shown in Fig. 1 the wall telephone has a projecting shelf support I within which the switch mechanism is mounted, and upon which the hand set is supported to operate the switch mechanism through the medium of the operating button 2. The switch as shown in Figs. 3 and 4 is mounted on the end portion of the bracket 3 of which only a part is shown. The bracket 3 is fastened at one end to the wall phone by means not shown. The bracket 3 is also fastened to the shelf of the telephone by the bushing 4 of the operating button 2, which is inserted through a hole in the shelf and screwed to bracket 3, thereby clamping the bracket 3 to the shelf. The switch as shown in Figs. 3, 4 and 5 comprises a metal plate 5 secured to bracket 3 by screws 6 and I. The metal plate 5 supports a pair of arms 8 and 8' as shown in Figs. 3 and 4 extending downward and supporting the spring combinations 9 and 9'. A stop I!) is formed out of plate 5 and extends downward to limit the movement of the lever I3. A pair of ears I I as shown in Fig. 3 and 4 extending down- Ward from the plate 5 provide a support for the pivot pin I2 for hinging the lever I3 which is provided with a pair of insulated bushings I4 for actuating the two sets of spring combinations 9 and 9. The tension stored in the spring combinations 9 and 9' tends to move the lever I3 upward (as seen in Fig. 3) toward the plate 5.

Also supported by plate 5 is the locking arm I5 which consists of a flat metal member held against the underside of plate 5 by means of the mounting screw 6. The mounting screw 6 has a shoulder which goes through a hole in the locking arm I5 and this screw also fastens the plate 5 securely to the bracket 3, leaving the locking arm free to pivot around the shoulder. The locking arm I5 has one arm extending upward as seen in Fig. 4 having a downwardly turned ear I6 which lies directly in front of the inner end of button IT. The arm I5 also has an extended portion having the downwardly turned ear or stop I8 which in normal position acts as a stop to hold lever I3 in its normal position as shown in Fig. 3. The whole arm is rotatable about screw 6 as its pivot and has a spring I9 normally tending to hold it in the position shown in Figs. 4 and 5. This tension spring I 9 as shown in Fig. 4 hooks on the side of one of the supporting arms 8 and goes upwardly at an angle to the opposite side of the other supporting arm 8 and then bends at an angle to the left around said arm 8' and fits in a groove in the tension spring guide 20. The tension spring guide 20 is securely fastened to the arm I5 adjacent to the ear I 6. Also securely fastened to the locking arm I5 is the stop 2I which consists of a pin extending out from the lower surface of arm I5 as shown in Figs. 4 and 5. This stop allows the looking arm I5 to move only the distance determined by the sides of the opening 22 in plate 5. The

ileg'to'provide a pivot point for the'clips.

3 button l1 moves inside a bushing 23 as shown in Fig. 6 which is fastened to the shelf 1 by the nut 24.

The switch is held in a normal position when the hand set is removed from the operating button 2 by'theilocking-arm l as shown' in Figs. 3, 4 and 5. To permit operation of the switch the release button I! is manually operated. The release button I! presses against the ear N5 of the locking arm, opposing the force of the tension spring 19, and moves the locking arm l5 downward as seen in Fig. 4. This will cause the stop l8, which normally prevents' lever l3 from operating when the hand set is removed from the operating plunger, to slideofi of the surface of lever l3. The lever [3 due to the tension of the springs on the bushings 14 will now operate and move the button 2 upwards. The movementof lever 13 allows the switching springs Band '9' to operate and switch the telephone circuits from a signallingtoa talking position.

With the switch in an operated position the stop [8 :rests against'the side of lever 13. When the hand set isplaced "on the operating plunger 2 the lever l3 moves downward until it hits stop ill. This movement of lever l3- releases stop i8 and theitension-spring'l9will operate the locking arm 15 'toiits initial position to lock the spring m'echanism in normal position again.

This locking mechanism prevents the switch- :ing contacts from operating when the hand set isremoved. Italso prevents false impulses irom "being sent over the line by the jarring or jigglinglof the hand set upon its removal from the .support.

Inaddition .to the locking mechanism just de- .=scribed 'apair'of wire spring clips are provided to :hold the handset in normal position. The 'pair of wire spring retaining 'clips 25 shown in Figs. 1 and 2 are pivotally mounted in the cradle of =.the wallphone and'tend-to hold the hand set in place. Eachwire spring clipis bent substantially U-shaped with an'eyelet 21 on the front These springclips fit in grooves cut in the'cradle, and a coil springlfi is fastened to the rear leg'of each :spring .clip to holdthe clips in place. The hand set is 'removed from the cradle by-pulling it forwardly against the tension of the springs 26 attached-to the rear'legs ofthe .clips until thefront set, a first button extending through thesupport and engaged at one end by the hand set when placed on said support, a lever for operating said springs engaged by the other end of said button, a flat metal locking arm inside said set with ears extending at right angles to the arm, a spring normally imaintaining -one =of -said ears in enz-gagement withsaid lever to ;prevent operation of said lever and said switching springs when the hand set is removed from said support, and

a second button normally engaging the other ear of said locking arm manually operative for operating saidlocking arm to permit operation of said lever :andsaid switching springs.

.2. Inxa handset telephone, a support for the hand set, switching springs in said telephone, a

lever operated by placing the hand set on its support for'tensioning said springs, a pivotal flat locking memberinside said support and having a normal locking position, an integral extending first arm of said locking member normally engaging said lever in .said locking position for locking said lever against movement when the handsetis-removed from said support, an integral extending second arm of said locking member havingthe outer end turned at right angles thereto, spring means in said support engaging said outerend of said secondarm fornorrnally holding said docking member and said first arm in said locking position whensaid hand set is removed from-its support, anda pushbutton means manually operated to engage said outer end of said secondarm and move said locking member and said first arm from :said locking position against the tensionof said spring means, said tension of said switching springs moving said lever in response to saidmovement of said member and said first arm from said locking position after said hand set has been removedfrom said support.

AMANDA OBERGFELL, Executrz'r of the Estate of Herbert F. Obergfell,

.Deceased.

REFERENCES CITED The following references 'are .of -record in the Jim of this :patent:

UNITED STATES PATENTS Number Name Date 980,619 Ewing Jan. 3, 1911 1,152,336 Myers Aug. 31, '1915 1,253,084 Newell Jan. 8, 1918 1,419,551 .Fleischman .'June 13, 1922 1,518,859 Levy .Dec. 9, 1924 1,762,746 Shann June 10, 1930 1,894,828 vObergiell Jan. 17, 1933 1,899,445 Miller :Feb. 28, 1933 2,036,010 Atkins Mar. 31, 1936 2,101,271 Schreiber -Dec. '7, 1937 2,106,299 Fourness Jan. 25, 1938 2,193,536 Murdock Mar. 31,1940 2,300,114 Golseth. v Oct.27, 1942 2,310,032 Matheison Feb. 2, 1943 

